Bhandari Hardik, Bhusal Kabi Raj, Banjade Sandhya, Bashyal Bibhav
Department of Internal Medicine, Gulmi Hospital, Tamghas, Nepal.
Department of Radiology, Lumbini Provincial Hospital, Butwal, Nepal.
Ann Med Surg (Lond). 2025 May 12;87(6):3969-3972. doi: 10.1097/MS9.0000000000003347. eCollection 2025 Jun.
Unilateral renal agenesis is defined as the congenital absence of renal tissue of one side that results from a lack of induction of the metanephric blastema by the ureteral bud. Primary retroperitoneal cysts lying in the retroperitoneal fatty tissue have no apparent connections with any anatomical structure except by loose areolar tissue and are rare. They remain asymptomatic and are diagnosed incidentally.
A 28-year female presented with complain of epigastric pain for 2 years. On examination, abdomen was soft and non-tender without any palpable masses. Abdominal ultrasonography revealed enlarged right kidney with left retroperitoneal cyst and absent left kidney. This finding was later confirmed by CT abdomen. The patient underwent ultrasound guided drainage of the lesion and a total of 300 ml of clear fluid was obtained. The fluid was examined to perform microbiological analysis and to exclude the presence of neoplastic cells. All tests were found to be negative.
Unilateral renal agenesis is associated with other congenital anomalies of the kidney, urinary tract. Retroperitoneal cysts are rare intra-abdominal tumors. The urogenital cysts arise from the vestiges of the embryonic urogenital apparatus and can be classified into pronephric, mesonephric, metanephric, and mullerian. In view of the anatomical location of these embryonal organs, the position of the retroperitoneal cysts can determine from which of the 3 divisions of the primitive urinary apparatus it arose. CT is ideal for assessing retroperitoneal cysts.
The occurrence of retroperitoneal cyst with congenital absence of ipsilateral kidney is a rare clinical phenomenon.
单侧肾缺如是指一侧肾组织先天性缺失，这是由于输尿管芽未能诱导后肾胚基所致。位于腹膜后脂肪组织中的原发性腹膜后囊肿，除通过疏松结缔组织外，与任何解剖结构均无明显联系，较为罕见。它们通常无症状，多为偶然发现。
一名28岁女性因上腹部疼痛2年就诊。检查时，腹部柔软，无压痛，未触及肿块。腹部超声显示右肾增大，左腹膜后囊肿，左肾缺如。腹部CT后来证实了这一发现。患者接受了超声引导下的病变引流，共引出300毫升清亮液体。对液体进行了微生物分析检查，并排除了肿瘤细胞的存在。所有检查结果均为阴性。
单侧肾缺如与肾脏、泌尿系统的其他先天性异常有关。腹膜后囊肿是罕见的腹内肿瘤。泌尿生殖系统囊肿起源于胚胎泌尿生殖器官的遗迹，可分为原肾、中肾、后肾和苗勒管囊肿。鉴于这些胚胎器官的解剖位置，腹膜后囊肿的位置可确定其起源于原始泌尿系统的三个部分中的哪一个。CT是评估腹膜后囊肿的理想方法。
腹膜后囊肿合并同侧先天性肾缺如是一种罕见的临床现象。
